4
6
GRÄSSLIN
2
bar
8
0
h
220V~50Hz
Z 52
UW
vom Kaltwassernetz
Nachfüllautomat Typ: NA 228
10
5
SPX
1996
TÜV / DVGW
230V ~
50/60 Hz
15
bar
16
0
30 Watt
Construction
The automatic refilling unit comprises:
● Powder coated pressed steel housing
● Drinking water and system connection with shutoff ball
valve
● Counter with reset key
● Electronic time relay
● Fault indicator lamp and cut-out button
● Pressure gauges for inlet and system pressure
● Discharge tundish
● ON/OFF switch
● 1.5 metre plug-in connection cable
● Water meter
● Bush for cable connection to a building management system
● Level control
● Electronic level probes
● Electronic level probes connection and 1 metre mass cable
connection prepared
* For temperatures above 100 ºC, the pressure at the highest point in the cold system
must be at least 1.0 bar above the operating pressure (static height plus 1.0 bar).
Subject to change 03/99
NA 228 S-C
Automatic refilling unit
for open heating systems
Product specification sheet
Application
The NA 228 S-C automatic refilling unit with DVGW-tested
backflow preventer permits the fixed connection of open
heating systems to the drinking water supply network.
It integrates a backflow preventer, a check valve and a water
meter in one single unit. The automatic refilling unit maintains
pressure between prescribed upper and lower limits in open
heating systems. It prevents back flow , back syphonage or back
pressure of the heating water into the potable water network.
Limitation of the refilling time is provided as well as the facility for
fast and automatic refilling of the system. In addition, build up of
steam in the system caused by pressure loss is prevented.
Special Features
● Components DVGW-approved
● Electrical changeover valve for control of the backflow
preventer
● Supplementary hot-water-resistant check valve for
increased protection of the drinking water network
● Setting facility for fast filling or refilling of the system
● Time relay, for limitation of the refilling period
● Standardised discharge connection
● Remote volt-free connection for electronic level probes and
mass cable
● Bush for cable connection to a building management system
● Circuit protection for volt-free connection
● Water meter, measures the refills
● Electronic level probes for level monitoring
Range of Application
The following operating data applies for the downstream system:
System pressure Maximum 4.0 bar
Temperature Maximum 120 ºC
Technical Data
Refilling Flow rate 110 litres/h at ∆p = 2.0 bar
Fast filling Flow rate finely adjustable between
110 litres/h and 1100 litres/h at ∆p=2.0 bar
Filling duration Adjustable between 5 and 100 minutes
Water level Upper and lower level indicated by
electronic level probes
Probes distance approx. 200 mm
Water inlet pressure Minimum 1.5 bar, maximum 4.0 bar
Remote connection 220 V, 50/60 Hz to activate compressor
level indicator switch „lack of water“
Volt-free contact
Supply voltage: 230V, 50/60 Hz
Power consumption: 30W
Connection size: R
1
/2" and Ø15
229
Automatic Refilling unit NA 228-SC
T
NETZ
EIN/AUS
zur Heizungsanlage
Fremdanschluß
- potentialfrei -
B
10
00 00 000 0
5
bar
15
0
16
Method of Operation
If the system pressure falls below the lower set value, for
example through leakage losses, then the changeover valve is
opened by electronic level probes control and thereby permits
water supply to the backflow preventer. The inlet pressure
moves the backflow preventer to the flow position and the
system is refilled until the pressure rises to the upper set limit.
The time period of the refill is monitored by the time relay. Once
the upper limit value has been reached, the level control closes
the changeover valve and the backflow preventer goes to the
H
shutoff position. The time relay then returns to the initial
position.
If the inlet pressure falls to the set pressure of the backflow
preventer during the automatic refilling operation, then the
backflow preventer (1 bar) automatically goes to the shutoff
position. The shutoff position of the backflow preventer is
indicated in the viewing window (green visible = shutoff
position)
Option
NA 228 S-C
Connection size R
1
/2"
Soldered connection size (mm) Ø15
Weight (approx kg) 16
Dimensions (mm)
H 380
B 370
T 160
Test Certificate Number 101/87/147
230
Braukmann Water Control . Honeywell AG
Subject to change 03/99
Installation Example
Automatic Refilling unit NA 228-SC
Installation Guidelines
● Fix appliance to wall
● Fit shutoff valves
❍ With shutoff valves
is possible -
maintenance and service without removal from the system
● Ensure good access
❍ Simplifies maintenance and inspection
● Check hydraulic connections for leaks
● Check time setting on time relay
Flow diagrams
Filling curves
Fast filling
Typical Applications
NA 228 S-C automatic refilling units permit a fixed connection
of open heating systems to the drinking water network.
Automatic refilling units are used:
● If the system pressure has to be maintained constant
● For fast and automatic refilling of the installation
● If build up of steam in the system caused by loss of
pressure must be prevented
● To limit the refilling time
Refilling
Setting
Flow rate V (litres/h)
∆p (bar)
Fast filling
Refilling Refilling
Subject to change 03/99 Braukmann Water Control . Honeywell AG
Refilling
Flow rate V (litres/h)
∆p (bar)
231
Automatic Refilling unit NA 228-SC
Spare Parts - NA 228 S-C automatic refilling unit
(1997 and onwards)
②
Description Part No.
① Water meter 0903110
② T ime relay 0903112
③ Changeover valve 0901407
④ Discharge tundish* 0901340
00 00 000 0
10
5
bar
15
0
16
⑤ Pressure gauge M 07 K - A16
⑥ Pressure gauge M 228 S - A8
for system pressure*
①
③
⑤
④
* Not visible in illustration
Subject to change 03/99
Braukmann Water Control . Honeywell AG
P.O. Box 1347
D - 74819 Mosbach-Germany
Phone:
(49) 62 61/ 06261/810 · Fax: 06261/8130 9 http://europe.hbc.honeywell.com
232
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